diff --git a/django/conf/locale/is/formats.py b/django/conf/locale/is/formats.py
index 1f122ad6b0..1b328eff1f 100644
--- a/django/conf/locale/is/formats.py
+++ b/django/conf/locale/is/formats.py
@@ -21,4 +21,4 @@ SHORT_DATE_FORMAT = 'j.n.Y'
 # DATETIME_INPUT_FORMATS =
 DECIMAL_SEPARATOR = ','
 THOUSAND_SEPARATOR = '.'
-# NUMBER_GROUPING =
+NUMBER_GROUPING = 3